Cutting of a soft food mass

ABSTRACT

Method and device for cutting a soft food mass, in particular for cutting machine-processed cheese, such as processed cheese or mozzarella, whereby the food mass is present as a broad food ribbon of small ribbon thickness, whereby the food ribbon is fed by means of a conveyor belt with a travel speed leading to a longitudinal cutting system, in particular in the form of a cutting roller, which cuts the food ribbon with axially arranged cutting disks into parallel longitudinal strips, whereby the direction of rotation of the longitudinal cutting system corresponds to the travel direction of the food ribbon, whereby the cutting disks in each case have blades that are provided with at least one tooth, whereby the tooth height is greater than the ribbon thickness, whereby the peripheral speed of the cutting roller is adjusted in such a way that a tooth is immersed in the food ribbon when cutting with the tips of the teeth and creates a slot of a specific slot length in the food ribbon that moves in the same direction, whereby the slot created by the subsequent tooth is adjacent to the preceding slot.

The invention relates to a method for cutting a soft food mass, inparticular for cutting machine-processed cheese, such as processedcheese or mozzarella, which is present as a broad food ribbon of smallribbon thickness, whereby the food ribbon is fed by means of a conveyorbelt with a travel speed leading to a longitudinal cutting device, inparticular a cutting roller, which cuts the food ribbon with axiallyarranged cutting disks into parallel longitudinal strips, whereby thedirection of rotation of the cutting roller corresponds to the traveldirection of the food ribbon. In addition, the invention relates to adevice for implementing the method.

In general, the longitudinal cutting of such broad food ribbons, inparticular also of processed cheese, is known from a series ofdocuments. By way of example, reference can be made to DE-OL 2 161 211,in which it is disclosed how a broad processed cheese ribbon is cut intoa corresponding number of more narrow longitudinal strips by means ofcutting disks that are arranged at preset intervals on an axis.

Similar devices are known from U.S. Pat. No. 5,601,855. There, i.a.,cutting rollers are disclosed that run on opposing rollers with smoothsurfaces or others whose cutting disks are interlocked. It is common toall of these devices that the peripheral speed of the cutting rollerscorresponds approximately to the travel speed of the conveyor belt andthat the paste-like processed cheese or the soft mozzarella stronglytends to adhere to the cutting rollers because of its stickyconsistency. In this case, in order to be able to ensure that the cutfood ribbons are not wound up with the cutting rollers, means arenecessary that are designed as scraping combs and that grip with fingersbetween the cutting disks and pull the sticky product out from betweenthe cutting rollers. In this method, the support contact between thecutting disks and the comb arrangement, on the one hand, and the foodproduct, on the other hand, is comparatively intensive, so that theseelements become heavily contaminated. The parts therefore often have tobe exchanged and cleaned, which results in a reduction of the servicelife.

The object of this invention is now to provide a method and acorresponding device for longitudinal cutting of a soft food ribbon,whereby method and device can be implemented with technically simplemeans and can lead to long service lives with low maintenance.

These objects are achieved by the method with the characterizingfeatures of Claim 1 and the device according to claim 7. Specialembodiments are named in the respective subclaims.

The essential idea of the invention is that the soft food ribbon (also“product” below), in particular the processed cheese or mozzarella thatis present as a flat ribbon, is not cut as before with slow-runningcutting disks with a smooth cutting action but rather “saws” withquick-running serrated longitudinal cutting disks, whereby in this case,this is not a machining process in the conventional sense. To this end,the longitudinal cutting disks are equipped with one or with severalteeth. The tooth or teeth are designed in this case so that they offerthe smallest possible support surface to the product and cleave the foodribbon almost “exclusively” with the tips of their teeth.

The direction of rotation of the cutting roller that is equipped withserrated longitudinal cutting disks, or “cutting sheets,” is in thetravel direction of the product. The rotational or peripheral speed isadvantageously adjustable and can thus be matched to the respectiverequirements. It has proven to be advantageous to adjust the peripheralspeed of the cutting rollers so that the tip of the tooth moves throughthe food at more than 1.2× or twice the travel speed, in particular at aspeed that is between 3× and 5× the travel speed. In comparison to thetravel speed, the peripheral speed advantageously can be adjusted sothat an integral slot is produced in the product.

According to the invention, the longitudinal cutting disks have bladesthat are provided with one or more teeth, in particular about 10 teeth,and their tooth height is greater than the thickness of the product, sothat the teeth should not be completely immersed into the food mass upto the tooth base. The peripheral speed of the cutting roller isadjusted so that the tip of the tooth moves relative to the movedproduct, and the slot that is introduced into the moving food ribbon asa result produces a predetermined slot length, whereby the slot that iscreated by the subsequent tooth, which can also be the same tooth in thecase of one tooth, at least almost directly adjoins the preceding slot.In this case, “directly” does not mean that an overlapping of two slotscannot also occur; the subsequent tooth thus engages in the slot of theprevious one. It may even be useful for certain products to be able tostand briefly in incompletely cut-through bridge areas betweensubsequent slots so that a certain cohesion remains between two parallellongitudinal strips. This cohesion can optionally facilitate theadditional processing, since parallel longitudinal strips cannot changetheir position relative to one another because of the hold.

The longitudinal cutting disks that are serrated according to theinvention have the significant advantage that the contact between thedisks and the product during cutting is interrupted in the meantime, sothat the friction between the longitudinal cutting disks and the productis greatly reduced. Moreover, in the cutting disks that are arranged inparallel at a small distance, the clamping surface that is effective forthe product is limited to a minimum. In contrast to the known cuttingdisks with smooth cuts, which separate the product by strongdisplacement, the surface of the longitudinal cutting disks that isreduced according to the invention leads to a reduction of the productdisplacement and thus also to preventing undesired product compression.

In this case, it has been shown that despite higher speeds, which on theperiphery of the cutting disks can reach essentially more than 4× thetravel speed, only a low tensile force is exerted on the product and,correspondingly, there is only a slight tendency that the product istorn during cutting. Because of the gentle treatment, the system isconsiderably less susceptible to interference with respect to theformation of folds in the product and to the dissolved productcomponents, which are transported through the cutting system on theproduct belt.

Since the product in this type of cutting processing according to theinvention can no longer wind around the cutting roller, it is possibleto completely dispense with the previously required scraping comb. Inaddition to the design simplification, still other advantages accompanythe elimination: in particular, the friction between the front surfacesof the cutting disks and the “comb teeth” as well as between the top ofthe product and the comb bottom facing the product is eliminated. Withthe friction that is significantly reduced overall between the productand the processing means, breadcrumb formation is greatly reduced. Thisfact contributes to the fact that the requirements on hygiene can easilybe sufficient with low purification effort. Alone, the reduced number ofcomponents ultimately reduces the purification effort.

Moreover, a reduction of the friction accompanies a correspondingreduction of the torque of the drive shafts and thus the mechanicaleffort as well as the costs. To reduce the friction still further, thecutting disks that are manufactured in the art from metal, in particularfrom stainless steel, are coated with a repellent material, for examplea plastic, such as PTFE or FEP, in an especially advantageousembodiment.

In another advantageous embodiment, the serrated cutting disks that arearranged on the common shaft are oriented such that the teeth ofadjacent cutting disks are arranged with their teeth offset to oneanother. In this way, the contact with the product can be even furtherreduced. In particular, it has proven advantageous to arrange in anoffset manner a cutting disk between two cutting disks that are arrangedsimilarly, whereby their teeth in each case lie amidst the tooth gaps ofthe adjacent cutting disks, so that an offset arrangement with a ½ toothspacing is achieved. With this offset arrangement, the clamping surfacebetween two parallel cutting disks is especially efficiently reduced.Moreover, the detaching force that acts on the product, which acts whenthe tooth comes up onto the product that is on the conveyor belt, is atleast partially offset by the compressive force of the adjacent tooththat is plunging into the product or resting on it. Another essentialadvantage of the offset arrangement is that the product can deviateduring the cutting process, i.e., during the product displacement causedby the tooth in the already present parallel cut gap. This effect alsoreduces the risk of adhesion to the cutting disks.

It is advantageous, moreover, relative to the design of the cuttingroller, to allow as great a variability as possible. To this end, thelatter is not designed integrally but rather built up modularly in asmuch as a number of individual cutting disks are stacked on a commonshaft in parallel and at a distance that is matched to the desiredproduct width. Correspondingly wide spacers are then provided betweenparallel cutting disks. Also, the outside diameter of the spacers can bematched with respect to the product thickness that is to be expected. Bythe modular design, a significant reduction of the cost of conversionwhen there is a change in the size of the product that is to bemanufactured is provided.

In this case, the components, such as the spacers and the cutting disks,can be selected separately and independently from the building block ofthe cutting roller. Thus, by changing the spacers to the same cuttingrollers, product strips of any width can be cut, whereby only thosesmall widths of the longitudinal strips of down to 2 mm can be cut. Nolimits are placed on excessive strip widths. Altogether, the ratio offree product passage and the groove depth between two cutting disks canbe optimally matched. In addition to the advantage of the greatvariability with respect to the product widths, the modular design makesit possible to separate the cutting rollers into individual parts thatare easy to clean. Another advantage is also that the exchange ofindividual cutting disks is possible in the case of repair.

The modular design is primarily also promoted in that no fingers of acomb engage in the grooves between the cutting disks, No specificdistances from the comb thus need to be maintained, so that the packetof cutting disks and spacers stacked on the shaft has a comparativelyhigh dimensional tolerance. Even a summation of the thickness tolerancesof the number of stacked elements does not necessarily run intoproblems. Because of the lower structural requirements, this greatertolerance produces considerable cost advantages.

A great variation of the product dimensions relative to width andthickness is ultimately provided by the elimination of the comb. Thecutting roller according to the invention allows a variation of up to 4×the product thickness, while the previous comb-equipped devices hadalmost no flexibility. Moreover, the longitudinal cutting disks can bematched to the product. Thus, various thicknesses of the cutting disksare possible, which in the case of processed cheese can vary from aribbon thickness of about 2 mm, for example between 0.3 mm and 0.8 mm.Also, the tooth shape and the number of teeth are variable and areadvantageously matched to the special product. The teeth can also havetoothbrushes that are ground sharply on one or both sides.

To achieve an extended arc-shaped contact of the tooth of the cuttingdisk with the conveyor belt or the subjacent axially parallelcounterpressure roller and therefore with the product, the conveyor beltcan be raised in the intake area by one unit, in particular by about 0.5mm to 2 mm. This can result in a reduction of the peripheral speed ofthe cutting disk by about 30%.

An especially advantageous application for the longitudinal cutting of acheese belt into narrow longitudinal strips, according to the invention,is the production of small cheese cubes or sticks. The effect of this isa subsequent cross-cutting of the narrow longitudinal strips. The cheeseribbon itself can also be produced just before longitudinal cutting by ashaping device, whereby the latter in particular has rollers or steelbelts that roll the heated liquid product up to the cheese ribbon andcool the latter to below room temperature, for example to a temperatureof between 6° C. and 10° C. until its soft or paste-like consistency isproduced. Advantageously, such a product line is designed to generatecubes or sticks in such a way that the product rests on a conveyor beltduring the entire longitudinal cutting process until just beforecross-cutting. Thus, on the one hand, product transfers from the wide,longitudinally cut product belt and, on the other hand, negative effectson the product by friction forces on the product surface as well asbuckling are avoided.

Depending on the application, it may be useful to equip the cuttingdisks with a one-toothed or multi-toothed blade. The variant with onlyone tooth per cutting disk has the advantage that with the offsetarrangement of the teeth of adjacent cutting disks, there is an evengreater lateral distance from the tooth that is to plunge in next. Onthe other hand, the cutting disks can be more narrowly packed so thateven especially narrow strips can be cut easily. Finally, there is this:the larger the lateral distance, the smaller the risk of the productbelt becoming jammed or being pulled up. Overall, the product restsbetter on the conveyor belt.

In the case of the one-toothed variant, however, a higher peripheralspeed than in the multi-toothed variant can be provided to produce anintegral section. It has turned out, however, that such a higher cuttingspeed is also accompanied by a better cutting function. In particular,the cutting with the one-toothed variant results in an improvedseparation in the product, in particular if the latter, like mozzarella,is especially fibrous. It has also proven advantageous that in theone-toothed variant, lower tensile force is introduced into the product,and the product thus experiences a smoother treatment. Also, the factthat less friction between tooth and product is produced with one toothcontributes to gentler treatment. Since one tooth is always immersed inthe same section, breadcrumb formation is reduced. Overall, thecross-sectional image is considerably improved, which increases theattractiveness of the product There is also another advantage in thatthe cutting roller can be cleaned more easily because of the smallernumber of teeth.

BRIEF DESCRIPTION OF THE DRAWINGS

Below, the invention is explained in more detail based on FIGS. 1 to 3.Here:

FIG. 1 shows: a section through a cutting roller,

FIG. 2 shows: a cutting sheet that is provided with one tooth,

FIG. 3 shows: a portion of a device for cutting processed cheese,

FIG. 4 shows: a cutting sheet that is provided with one tooth, and

FIG. 5 shows: a cutting roller with one-toothed cutting sheets.

FIG. 1 first shows a section through cutting roller 1, one roller body 2with a shaft journal 3 that is arranged on the front. This cuttingroller 1 is driven by means of a gear on a gear rim 4 that is arrangedon one side. The cutting roller 1 that is shown here has a sectionalwidth of about 550 mm with a diameter of about 150 mm, and it cuts aflat cheese ribbon of this width into longitudinal strips ofapproximately 3 mm in width. Approximately 180 cutting disks 5 arecorrespondingly applied to the roller body 2 and are separated from oneanother by spacers 6 (FIG. 1a ) that are also applied to the roller body2. Such a cutting disk 5 is shown in FIG. 2.

Nine cutting teeth 7 that are distributed over the periphery and thatonly penetrate the tips 8 of the teeth in the product 9 and in this case“split” the product 9 to a specific length can be seen clearly. Thetravel direction of the product 9 is identified with arrow A, and thedirection of rotation of the cutting roller 1 is identified with thearrow B. The cutting teeth 7 of the cutting disk 5 have a tooth height10 that is greater than the thickness of the product 9, so that thecutting teeth only penetrate the tips 8 of the teeth in the product. Thedriving means that acts on the gear rim 4 drives the cutting roller at atrack speed that is measured at the periphery and that corresponds to atleast twice the travel speed. Because of the convex-curved toothbrush11, the cutting teeth have a comparatively small cutting angle incomparison to the moving product. So that the contact with the productis reduced to a minimum, the backs 12 of the teeth of the cutting teeth7 have a clearly concave curvature.

It can also be seen from FIG. 1 at the different heights of the tips 8 aand 8 b of the teeth that adjacent cutting disks 5 a and 5 b with theircutting teeth 5 are arranged offset to one another by a ½ tooth spacing,in such a way that teeth of one cutting disk in each case lie amidst thetooth gaps of the adjacent cutting disk. Cutting disks 5 and spacers 6are stacked alternately on the roller body 2 and are held snugly via agroove 13 on a border that is provided on the periphery of the rollerbody. The gap depth 14 of the tips 8 of the teeth on the outsidediameter of a spacer 6 is approximately 12 mm. The spacers 6 have athickness of three mm, such that with this device, product strips ofthis width are cut.

In FIG. 3, a portion of a device for cutting the paste-like processedcheese that is formed in a flat ribbon 15 is shown that cuts the latterinto a number of parallel longitudinal strips. The processed cheese 15is conveyed at travel speed on a conveyor belt 16, which runs over driveand deflection rollers 17. Below the conveyor belt 16, a scraping device20 is arranged that cleans adhesive product from the surface of theconveyor belt 16.

A cutting roller 25, which has a number of cutting disks 19 that arearranged axially at intervals, is arranged on the conveyor belt 16.Drive means 18 in the form of a gear drive the cutting roller 25. Alsohere, the offset arrangement of the teeth of the cutting disks 19 a and19 b can be seen around a ½ tooth spacing. The complete cutting roller25 is located over the product ribbon 15 and can be pivoted out to theoperating side for cleaning and for format change with little effort bymeans of a pivoting frame. The teeth of the cutting disks 19 aredimensioned such that they reach up to the conveyor belt 16. The axis ofthe cutting roller 25 is arranged in such a way that the deflectionroller 17 a offers a thrust bearing to the cutting roller 25. Driving isdone via an axially parallel drive shaft, whereby the torque isintroduced into the cutting roller 25 via a gear pair.

In this case, a cross-cutting device 21 that rotates in the direction ofthe arrow is arranged just behind the cutting roller 25. The latter hasshear blades 22 that shear off product 15, now cut into strips, over anedge 23. The individual product cubes 24 then fall into a correspondingvessel.

FIG. 4 shows a cutting sheet 26 that is provided with a tooth, wherebythe direction of rotation is symbolized by the arrow C. One tooth 27 ofthe cutting sheet 26 has a steeper but convex-curved toothbrush 28 incomparison to the teeth 7 and a tooth back 29 that is only slightlyconcave. The cutting sheet 26 is held snugly on a shaft by means ofgrooves 30 that are arranged on the inner periphery.

FIG. 5 shows a cutting roller with a shaft 31 on which a number ofclosely packed one-toothed cutting sheets are “threaded” and are heldsnugly in the described way. It can be clearly seen that the offsetarrangement of the teeth 32 and 33 results in two adjacent cuttingsheets that causes these two teeth to follow one another in thedirection of rotation (arrow D), and an enlarged lateral distance 34 ispresent between two simultaneously immersing teeth.

The invention claimed is:
 1. A longitudinal cutting device for cutting afood that is in the form of a flat ribbon into a number of parallellongitudinal strips comprising: (a) a longitudinal cutting system (1,25) comprising multiple coaxially arranged serrated cutting disks (5)mounted in a fixed relationship to each other for cutting a flat ribbonof a food into a number of parallel longitudinal strips, wherein (1)each serrated longitudinal cutting disk (5) has at least one cuttingtooth (7, 27) and (2) the at least one cutting tooth (7, 27) of eachserrated longitudinal cutting disk (5) is radially offset relative tothe at least one cutting tooth (7, 27) of each next adjacent serratedlongitudinal cutting disk (5) to reduce clamping of a food mass betweenadjacent serrated longitudinal cutting disks (5); (b) a driving devicecapable of transferring rotational force to the longitudinal cuttingsystem for rotating the longitudinal cutting system about the axis ofthe coaxially arranged serrated cutting disks (5); and (c) a conveyor,wherein the conveyor is arranged to have a travel direction parallel tothe axially arranged serrated cutting disks (5) and proximal to, or incontact with, the tooth tip (8) of each serrated longitudinal disk (5)when the longitudinal cutting system (1, 25) is rotated, wherein eachserrated cutting disk (5) of the longitudinal cutting system has acutting direction parallel to the travel direction of the conveyor. 2.The longitudinal cutting device according to claim 1, wherein eachserrated longitudinal cutting disk (5) has only one cutting tooth (7,27).
 3. The longitudinal cutting device according to claim 1, whereineach serrated longitudinal cutting disk (5) comprises multiple cuttingteeth (7, 27).
 4. The longitudinal cutting device according to claim 1,wherein each cutting tooth (7, 27) has a convex tooth face (11).
 5. Thelongitudinal cutting device according to claim 1, wherein each cuttingtooth (7, 27) has a concave tooth back (12).
 6. The longitudinal cuttingdevice according to claim 5, wherein each cutting tooth (7, 27) has aconcave tooth back (12).
 7. The longitudinal cutting device according toclaim 1, wherein the conveyor is arranged to have a travel directionparallel to the axially arranged serrated cutting disks (5) and proximalto, or in contact with, the tooth tip (8) of each serrated longitudinaldisk (5) when the longitudinal cutting system (1, 25) is rotated.
 8. Asystem comprising the longitudinal cutting device according to claim 1and a shaping device associated with the conveyor, wherein the shapingdevice comprises steel belts suitable for shaping and cooling a liquidcheese product into a ribbon having a soft or paste-like consistency. 9.A system for cutting a soft food ribbon into cubes or sticks comprisingthe longitudinal cutting device according to claim 1 and a cross-cuttingdevice proximal to the conveyor of the system for cutting a soft foodribbon into a number of parallel longitudinal strips, wherein thecross-cutting device is suitable for cross-cutting parallel longitudinalstrips formed by the system to form cubes or sticks as the longitudinalstrips are advanced by the conveyor.
 10. A system for cutting a softfood ribbon into cubes or sticks comprising the system for cutting asoft food ribbon into a number of parallel longitudinal strips accordingto claim 8 and a cross-cutting device proximal to the conveyor, whereinthe cross-cutting device is suitable for cross-cutting parallellongitudinal strips formed by the longitudinal cutting device to formcubes or sticks as the longitudinal strips are advanced by the conveyor.